I played squash for about 10 years to a reasonably good standard. It's incredibly fun and a fantastic workout. Unfortunately my knees have given up after all the lunging and I had to stop playing.
To get the most of your time on the court warm up before you start playing, especially in winter when done courts can get quite cold.
Roll the ball under your foot to get it warm quickly. If you don't have good technique warming up a cold ball in as cold court is a nightmare!
Technique and footwork is everything in squash. Watch some training videos to learn how to position yourself at the T and how to move around your opponent efficiently.
Unlike tennis you have to strike the ball with the racquet face "open", palm facing up and you swing your whole arm and upper body to generate power and speed. Your swing ends with your racket over the other shoulder.
Footwork: Opposing foot is planted when you strike the ball. So for right handed forehand shot you'd have your left foot planted ahead of the right one and you'd be swinging to strike the ball when it's inline with your foot.
With experience,from the T you should be able to get to each corner of the court in 3 strides/lunges. The Pros make it look effortless, but they're constantly reading their opponents body language and working out where to be for the next shot.
Oh, good non marking shoes and a dust free court make a massive difference too!